2 rubber stamps cost $2.22. Which equation would help determine the cost of 14 rubber stamps?
There are several equations that could help determine the cost, each with a slightly different approach. We know the cost of 2 rubber stamps. We want to know the cost of 14 rubber stamps. We can write the numbers of rubber stamps as a proportion: $\dfrac{2}{14}$ We know 2 rubber stamps costs $2.22. We can let $x$ represent the unknown cost of 14 rubber stamps. The proportion of these costs can be expressed as: $\dfrac{\$2.22}{x}$ The cost changes along with the number of rubber stamps purchased, and so the two proportions are equivalent. $\dfrac{2}{14} = \dfrac{\$2.22}{x}$